Problem: $\overline{AC}$ is $3$ units long $\overline{BC}$ is $4$ units long $\overline{AB}$ is $5$ units long What is $\sec(\angle ABC)?$ $A$ $C$ $B$ $3$ $4$ $5$
Solution: $\sec(\angle ABC) = \dfrac{1}{\cos(\angle ABC)}$ How can we find $\cos(\angle ABC)$ SOH CAH TOA osine = djacent over ypotenuse Adjacent $= \overline{BC} = 4$ Hypotenuse $= \overline{AB} = 5$ $\cos(\angle ABC) = \dfrac{4}{5}$ $\sec(\angle ABC) = \dfrac{1}{\cos(\angle ABC)} = \dfrac{5}{4}$